Greetings, SETI enthusiasts. As someone who primarily works "at arm's length" from the SETI@home/BOINC group most of the time, I mostly want to use my blog to give a behind-the-scenes perspective of what goes on here, from a sort of "fly-on-the-wall" point of view. I hope such a thing would be entertaining as well as informative. I guess that remains to be seen...hence the blog title, The Outsider's Inside View. Don't like it? Then suggest something else. I thought "The ET Insider" might get me in trouble with Paramount. Not that I watch such dreck anyway.

So who am I and what do I do? I am a postdoc and I study the interstellar medium of our Galaxy. I was brought to UC Berkeley by Eric Korpela, to analyze the atomic hydrogen (HI) spectra created as a (by)product of recording all this SETI@home data. We call this project SETHI, and I've been making datacubes from the over 14-million HI spectra taken with the Arecibo line feed. I do all sorts of other interesting radio astronomy work, about which I can bore you in a later post. My other SETI@home activities are fairly limited - but I attend the weekly Group and Science meetings, which I'm sure will be the source of many sardonic ramblings on these boards (at least until I'm told to stop). Apart from the above, I occasionally get roped in by Dan to help out with anything from confirming telescope pointing data to processing donation cheques.

Seeing as how this is a forum, that means we should talk. Besides SETI & radio astronomy, I have loads of other interests. I think the world would be a happier place if everyone owned a Mike Keneally CD. I am from Canada, and I am a huge hockey fan. Lately I've been dreaming about caves. Is that enough to get things going?

So what else can I say by way of introduction? It might appear that I have rather few credits, being part of the staff and all. There are two reasons for that, one being that I actually have to compete with SETI@home/BOINC processes on most of the machines I use to do my scientific processing. So I probably deserve about 0.1% of Eric's credit, since he's got SETI@home running on so many processors here. The other reason (the real reason, in fact) is that my laptop's hard drive burned out and I haven't installed BOINC on the replacement drive yet (nor am I sure I will).

It's my hope to post a new thread once a week, and if anyone cares to respond with questions, comments, diversions, etc, I will try to answer prior to the next new thread. Is that good board etiquette? I've no idea, but that's my plan for now.

I was brought to UC Berkeley by Eric Korpela, to analyze the atomic hydrogen (HI) spectra created as a (by)product of recording all this SETI@home data. We call this project SETHI, and I've been making datacubes from the over 14-million HI spectra taken with the Arecibo line feed. I do all sorts of other interesting radio astronomy work, about which I can bore you in a later post.

Thanks for the post Kevin.

So is there something special about the Hydrogen Spectra that we have been working on, on our home computers?

Are you looking for anything in particular?

What kinds of things could you potentially see in the data to make you stop and think "Ooh, that's interesting!"?

What's a datacube?

What is an 'average' day or week like in the SETI/BOINC team?

I, and I'm sure many others too, am looking forward to being 'bored'.

Join TeamACC
Sometimes I think we are alone in the universe, and sometimes I think we are not. In either case the idea is quite staggering.

Thank You for making this known... Now some people know where the other half of Eric's time goes... As Near I can figure he is juggling about 6 or 7 Half's.

Pappa

Greetings, SETI enthusiasts. As someone who primarily works "at arm's length" from the SETI@home/BOINC group most of the time, I mostly want to use my blog to give a behind-the-scenes perspective of what goes on here, from a sort of "fly-on-the-wall" point of view. I hope such a thing would be entertaining as well as informative. I guess that remains to be seen...hence the blog title, The Outsider's Inside View. Don't like it? Then suggest something else. I thought "The ET Insider" might get me in trouble with Paramount. Not that I watch such dreck anyway.

Hello Kevin. Welcome to the board. I am (a) Misfit. If you encounter any problems in your work feel free to blame me for it. In fact I've heard rumors of a "Blame Misfit" button starting in BOINC version 6. :-DJoin BOINC Synergy!

I'm known as Fuzzy Hollynoodles (among others) and I have been around for some time here.

I look forward to read your posts, it sounds interesting what you are doing. And as I'm not in this for ET, I'm happy to learn that the data from this project and maybe from our crunching is used for science in your field.

So is there something special about the Hydrogen Spectra that we have been working on, on our home computers?

Well, as I understand it, the 100-MHz bandwidth of SETI@home is divided into 40 2.5-MHz wide 'boards,' and I am only looking at Board 19, centered on 1420.0 MHz, since the 1420.4 MHz HI line falls in there. I think SETI@home data can come from any of the 40 boards, so less chance of picking up the spectral line.

Are you looking for anything in particular?

Eventually, yes. For now it will be an accomplishment just to get the survey done, ie. get all the datacubes made. So far 52 of my 144 datacubes are made. #53 should be finishing later today.

What kinds of things could you potentially see in the data to make you stop and think "Ooh, that's interesting!"?

Well, we know that interstellar hydrogen traces much of the structure of the Milky Way. We see all sorts of beautiful structures, from filaments to shells.

What's a datacube?

A datacube is a three-dimensional image, which we can create because we measure the HI line across many contiguous frequencies. So whereas an astronomical 'map' is a 2-d representation of the intensity on the sky (the dimensions are some sky coordinate pair, eg. right ascension & declination), we can map the HI line at each frequency we measure, and that corresponds to HI gas at a slightly different velocity with respect to us. Putting all those maps together in a stack, we get a 3-D dataset that we can view in 'movie mode' to trace out HI structures. What a cool job I have.

What is an 'average' day or week like in the SETI/BOINC team?

Well, I figure that's something for the interested reader to try and glean from our blogs, n'est-ce pas?

Another dream about caves last night/this morning. My 9-yr-old son has asked me to try and keep track of my dreams and they've all been taking place in caves and other enclosed places lately. The coolest caves I've been to are the Camuy Caves that are about 30 minutes' drive from the Arecibo Observatory.

A datacube is a three-dimensional image, which we can create because we measure the HI line across many contiguous frequencies. So whereas an astronomical 'map' is a 2-d representation of the intensity on the sky (the dimensions are some sky coordinate pair, eg. right ascension & declination), we can map the HI line at each frequency we measure, and that corresponds to HI gas at a slightly different velocity with respect to us. Putting all those maps together in a stack, we get a 3-D dataset that we can view in 'movie mode' to trace out HI structures. ...

Is that velocity assumed to represent distance (Hubble constant an' all that) or do you also see galactic drift?

Are you having to rerun all the tapes yourself or do you have to wait for whatever Matt psuedo-randomly squirts onto the disks?

[quote]
A datacube is a three-dimensional image, which we can create because we measure the HI line across many contiguous frequencies. So whereas an astronomical 'map' is a 2-d representation of the intensity on the sky (the dimensions are some sky coordinate pair, eg. right ascension & declination), we can map the HI line at each frequency we measure, and that corresponds to HI gas at a slightly different velocity with respect to us. Putting all those maps together in a stack, we get a 3-D dataset that we can view in 'movie mode' to trace out HI structures. ...

Is that velocity assumed to represent distance (Hubble constant an' all that) or do you also see galactic drift?[\\quote]

It's almost entirely because of the rotation of our Galaxy, but yes the velocity can still be used to infer distance if we have a good model of the rotation.

Are you having to rerun all the tapes yourself or do you have to wait for whatever Matt psuedo-randomly squirts onto the disks?

Matt splits the tapes for hydrogen for me. Once a spectrum enters the database I make a "beamfile" for it so I can properly weight the spectra when I make my cubes.

I have a few results on a website but not much just yet. Currently I have 14 SETHI cubes being crunched. 3 are on thumper, the master science database server. Any more than 3 and I'll incur the wrath of Bob. Three more are on ewen, which I think of as 'my' machine because we bought it for HI stuff, not SETI@home work. The remaining 8 are on a machine called lando, one of our newer multi-core systems. We have another one, sidious, that I'm waiting to be made available again so I can run about 6 more on that machine. It's having a few problems at the moment (I can tell you're all shocked to hear we have problems with our computers).

Some tidbits from our science meeting yesterday. It's hoped that in February we'll have a client that will be ready to distribute SETI@home data from the new multibeam receiver (ALFA). This is by far a superior instrument than the line feed which has taken data since the inception of SETI@home - seven positions on the sky at once, and two polarizations per beam, so 14 times as much data to crunch, with much better systematics too. We have a student who's working on several graphics projects, so hopefully that will translate into more informative webpages for you all to read. Astropulse is coming along as well - there might be a client ready for beta testing quite soon. There's a large conference on Astrobiology in Puerto Rico this summer, at which SETI@home will try to have a significant presence - I'm supposed to write a paper on the spinoff benefits of SETI@home. As far as I can see there are at least three areas in which SETI@home has made an impact - computationally, technologically, and scientifically. Perhaps in a cultural way too? I'd be interested in opinions on this topic from people on the boards. Let me know what you think.

The remaining 8 are on a machine called lando, one of our newer multi-core systems. We have another one, sidious,

Sorry to be way off topic, but in some relation to what you posted, are you/they naming your/their servers after Star Wars characters? Lando Calrissian and Darth Sidious? That's kinda cool if you/they are Star Wars fans.

Is that velocity assumed to represent distance (Hubble constant an' all that) or do you also see galactic drift?

Just to elaborate a bit on what Kevin said, the Hubble constant relating apparent recession-velocity to distance only applies on very large intergalactic scales, at which gravity becomes extremely weak and over which space is nearly flat. Itâ€™s no use at all within the Milky Way, where all the stars, gas, and dust are bound together in a common â€˜gravity wellâ€™. Even our Local Group of galaxies is too small to follow the Hubble relation: indeed, an averaged spectrum from our Galaxyâ€™s â€˜big brotherâ€™ the Great Andromeda Galaxy (AKA M31 or NGC 224), at a distance of the better part of a megaparsec, actually shows a blue-shift. This indicates that itâ€™s getting closer to us (or vice versa) rather than farther away, showing that gravity can still trump space-expansion over that range. Red-shift only becomes a reliable measure of distance at ranges from tens of Mpc up to Gpc. (A parsecâ€”short for â€œparallax-secondâ€â€”is about 3.26 light-years.)

The remaining 8 are on a machine called lando, one of our newer multi-core systems. We have another one, sidious,

Sorry to be way off topic, but in some relation to what you posted, are you/they naming your/their servers after Star Wars characters? Lando Calrissian and Darth Sidious? That's kinda cool if you/they are Star Wars fans.

Yep, we ran out of Simpsons characters and aliens with names that start with K.

I assume we'll have a vader at some point, too. Sidious is supposed to turn into a replica of the BOINC/user database machine, but it keeps on forgetting how many processors it has, hanging, and/or refusing to reboot properly.

That's fine, if a bit annoying, for what Kevin does. As a high reliability database machine, it needs a bit of work before we can rely on it.

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Kevin's work is to finish up what we first started here.
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The remaining 8 are on a machine called lando, one of our newer multi-core systems. We have another one, sidious,

Sorry to be way off topic, but in some relation to what you posted, are you/they naming your/their servers after Star Wars characters? Lando Calrissian and Darth Sidious? That's kinda cool if you/they are Star Wars fans.

Yeah, I like Star Wars just fine. I think it was Court who named these last two. It's kind of a slippery slope, though. You could get some awful names for machines if you made that your theme for your whole LAN. Lately sidious has been behaving more like a jarjar. But I see that overnight Eric has reconfigured it so I can crunch more SETHI data on it, so I've got 6 more jobs up and running. Three of my other cubes finished overnight, so I've got 58 completed, 86 more to go, and 20 currently being crunched on 4 different machines. I have to say, the excellent level of computing support I get is one of the things that helps me enjoy my work so much.

Yeah, I like Star Wars just fine. I think it was Court who named these last two. It's kind of a slippery slope, though. You could get some awful names for machines if you made that your theme for your whole LAN. Lately sidious has been behaving more like a jarjar. But I see that overnight Eric has reconfigured it so I can crunch more SETHI data on it, so I've got 6 more jobs up and running. Three of my other cubes finished overnight, so I've got 58 completed, 86 more to go, and 20 currently being crunched on 4 different machines. I have to say, the excellent level of computing support I get is one of the things that helps me enjoy my work so much.

What kind of comedy is this all of the danger youâ€™ve discovered
What kind of comedy is this how can you say now youâ€™re frightened
You labeled me in forty tries and in case you didnâ€™t realize
I was a landscape in your dream and all my mountains were on fire

What kind of labyrynth is this that weâ€™re constructing through talking
What kind of labyrynth is this that sends you laughing without smiling
Age brings a sad little surprise and in case you didnâ€™t realize
While you were calculating tears my head expired